Dr. Schofield says: "It is quite true that the range of the unconscious mind must necessarily remain indefinite; none can say how high or low it may reach.... As to how far the unconscious powers of life that, as has been said, can make eggs and feathers out of Indian corn, and milk and beef and mutton out of grass, are to be considered within or beyond the lowest limits of unconscious mind, we do not therefore here press. It is enough to establish the fact of its existence; to point out its more important features; and to show that in all respects it is as worthy of being called mind as that which works in consciousness. We therefore return to our first definition of Mind, as 'the sum of psychic action in us, whether conscious or unconscious.'" Hartmann calls our attention to a very important fact when he says: "The unconscious does not fall ill, the unconscious does not grow weary, but all conscious mental activity becomes fatigued." Kant says: "To have ideas and yet not be conscious of them--therein seems to lie a contradiction. However, we may still be immediately aware of holding an idea, though we are not directly conscious of it." Maudsley says: "It may seem paradoxical to assert not merely that ideas may exist in the mind without any consciousness of them, but that an idea, or a train of associated ideas, may be quickened into action and actuate movements without itself being attended to. When an idea disappears from consciousness it does not necessarily disappear entirely; it may remain latent below the horizon of consciousness. Moreover it may produce an effect upon movement, or upon other ideas, when thus active below the horizon of consciousness." Liebnitz says: "It does not follow that because we do not perceive thought that it does not exist. It is a great source of error to believe that there is no perception in the mind but that of which it is conscious." Oliver Wendell Holmes says: "The more we examine the mechanism of thought the more we shall see that anterior unconscious action of the mind that enters largely into all of its processes. People who talk most do not always think most. I question whether persons who think most--that is who have most conscious thought pass through their mind--necessarily do most mental work. Every new idea planted in a real thinker's mind grows when he is least conscious of it." Maudsley says: "It would go hard with mankind indeed, if they must act wittingly before they acted at all. Men, without knowing why, follow a course for which good reasons exist. Nay, more. The practical instincts of mankind often work beneficially in actual contradiction to their professed doctrines." The same writer says: "The best thoughts of an author are the unwilled thoughts which surprise himself; and the poet, under the influence of creative activity, is, so far as consciousness is concerned, being dictated to."